In the west African country where there are many more twins than anywhere else in the world, photographers Bénédicte Kurzen and Sanne de Wilde explore ‘double birth’ and its mythology

Ten young people pose for a group shot, boys in front, girls behind. Almost identically dressed, they stare straight to camera with a mixture of shyness and defiance familiar from school photographs the world over. But the brightness of their uniform, the playfulness of their headgear, suggests that this is no ordinary gathering – and indeed it is not. These children, togged out in their holiday best, were among more than 2,000 sets of twins who poured into the Nigerian town of Igbo-Ora last autumn for the state of Oyo’s first twins festival – an event celebrating the town’s claim to be the twins capital of the world.